Coastal protection seawalls

An interesting cost effective and soft alternative to conventional seawalls for coastal protection against erosion are artificial reefs which have the advantage... 

Various coastal structures, as already discussed, can be applied to solve, or at least, to reduce erosion problems. They can provide direct protection (seawalls, dikes, revetments) or indirect protection (groins and offshore breakwaters of various designs), thus reducing the hydraulic load on the coast (Fig. 20.4). Rock and concrete are usually the construction materials. 

The physical protection system uses zoning principles for floating NPPs there is a water area, limited by seawalls, coastal service areas and the floating power unit area, which is a high control zone. 

A second type of coastal structure consists of a mound or layers of quarried rock fill, protected by rock or concrete armour units (Fig. 14.2). The outer armour layer is designed to resist wave action without significant displacement of armour units. Under-layers of quarry or crushed rock support the armour and separate it from finer material in the embankment or mound. These porous and sloping layers dissipate a proportion of the incident wave energy in breaking and friction. Simplified forms of rubble mounds may be used for rubble seawalls or as protection to vertical walls or revetments. Rubble mound revetments may also be used to protect embankments... 

These advances, together with numerous advantages of GSCs as soft rock, have contributed to extend the use of GSCs to permanent coastal defenses, including a wide range of types of structures such as seawalls, revetments, groins, artificial reefs, offshore breakwaters, perched beaches, dune reinforcement, core of rubble mound structures, scour protection, etc. (Fig. 21.1). 

---